• IPC says close to a quarter of Gazans in famine
• Israel calls report false, says it serves Hamas
• First time IPC has determined a famine outside of Africa
• UN aid chief says famine could have been prevented

UNITED NATIONS, Aug 22 (Reuters) - Gaza City and surrounding areas are officially suffering from famine, and it will likely spread, a global hunger monitor determined on Friday, an assessment that will escalate pressure on Israel to allow more aid into the Palestinian territory.

The Integrated Food Security Phase Classification (IPC) system said 514,000 people - close to a quarter of Palestinians in Gaza - are experiencing famine, with the number due to rise to 641,000 by the end of September.

Some 280,000 of those people are in a northern region covering Gaza City - known as Gaza governorate - which the IPC said was in famine following nearly two years of war between Israel and Palestinian militants Hamas.

It was the first time the IPC has recorded famine outside of Africa, and the global group predicted that famine conditions would spread to the central and southern areas of Deir al-Balah and Khan Younis by the end of next month. It added that the situation further north could be even worse than in Gaza City, but limited data prevented any precise classification. Reuters has previously reported on the IPC’s struggle to get access to data required to assess the crisis.

“It is a famine that we could have prevented had we been allowed,” said U.N. humanitarian chief Tom Fletcher. “Yet food stacks up at borders because of systematic obstruction by Israel.”